Two-cycle gas engine



' Feb. 23 1926. 1,574,062

R. J. BOEHMER l TWOCYCLE GAS ENGINE Filed oct. 5. 1922 MX g PatentedFeb. 23, 1926.

UNITED STATES PATENT OFFICE.

VRUDOLPH J'. BDEHMEB, OIF PORTLAND, OREGON.

TWO-CYCLE GAS ENGINE.

Application filed October 5, 1922. Serial No. 592,655.

To all whom 'it may concern.'

Be it known that I, RUDOLPH J. BonHMER, a citizen of the United States,residing at Portland, in the county of Multnomah and the State of,Oregon, and having his place of residence at 1487 Montana Avenue, insaid city and State, Vhave invented a new and useful lImprovement 'inTwo-Cycle Gas Engines, of which the following is a speci. fication.

My invention relatesrto an improvement in internal combustion enginesusing hydrocarbon material as the means of creating the combustion andthe improvement applies to the two cycle type, for in this type twoexplosions are obtained in each cylinder for each two cycles ofoperation of the cylinder instead of one in the four cycle type, my1nvention is a radical change in somerespects over the common type oftwo cycle engines, in that I have, in el'ect, two pistons in eachcylinder, one of which, has on its upper end, a valve head, instead ofone, and both of the pistons carrying piston rings, a further change isthat the intake valves are in the side of the vertical cylinder walls,one on either side, and the spark plug or means of ignition is alsolocated on the side at the point of explosion, the motor is so designedthat the upper piston, after the explosion of the charge and expansiontakes place, moves in a rapidly accelerated movement downward andcompletely exhausts the charge of burned gas and then, in turn, isaccelerated in the upward movement ,in advance of the travel of theoperating piston, completely causes a ,or sufficient area to permit thefree second charge to be brought into the eX- plosion chamber and isseated before the ad vance of the explosion and operating piston,thereby creating a two cycle motor.

The upper piston has'a piston stem that passes through the cylinder headof the cylinder and to the exterior of the same and curing of the inletand exhaust valves to the cylinder walls whereby these valves may be,easy of access,to permit the repair, replacement, and grinding of thevsame as well as the valve seats.

The cylinder has a removable head which has a guide therein to permitthe passage of the piston stem therethrough, it also has `a valve seatmachined on the under side of 'the same to permit the seating of theupper valve head of the piston, the cylinder head also has ports casttherein to permit the passage of free air therethrough thus preventingthe forming of a vacuum on the downward passage of the upper piston,also preventing compression on the upward movement of the same.

For a better understanding of my inven tion reference is made to theaccompanying drawings and specications wherein a complete disclosure ofthe invention is made, and in which similar numerals refer to similarparts throughout the several views:

Fig. lis a section through the cylinder walls with the operating, orpower piston at the full up part of the str0ke,and in this position thecharge of gas is under full compression and the charge is to be fired.Fi 2 is a section view through the cylinder wal s also, but the power oroperating piston is at thefull, or down position, of the stroke, and thesecondary piston is at the full down stroke, also, clearly showing howcompletely this piston empties the cylinder of the exploded or spentgases. Fig. 3 is a detached side view of the exterior of the cylinderwall illustrating the port and the means of attaching the valve membersthereto.

Similar reference numerals refer to similar parts throughout the severalviews;

l is the cylinder wall and 2 is the cylinder head, 3 is the closurebase, 4 is the compression or power piston having piston rin s of theusual kind and construction, an attached to the piston in the customarymanner, 6 is the connecting rod attached to the piston by means'of awrist pin 7 and is operated by the crank 8, 9 is the upper pis- .tonwhich seats to a ground and close fitting adjustment provided at 2 inthe piston head, attached to the piston is piston ring 10. I wouldprefer not to be limited to the use of one ring only and it may be foundnecessary upon further experimentation to provide more than one pistonring of the usual type in this piston. The piston terminates 4 gagessproc et 27 mounted upon shaft 28 tov casting 34, seating pressue on itsupper end in a iston stem 11, which is connected with an actuates bellcrank 12 through pin 13 which is attached to the bell crank 12 and thesame o crates 1n a proper bearing 14 located 1n the upper end of stem11. Bell crank 12 is held in position by bracket 15 which hasv journaledtherein pin or shaft 16 about which the bell crank oscillates. Bellcrank 12 also has attached to it operating means through pin' or shaft17 being attached to rod 18, the pin 17 beingjournaled in suitablebearings in the bell crank and being actuated by the movement of rod 18which is secured at its lower end through the means of bearing 19attached or secured to stem 20, this bearing is attached to stem 20 andthe rod 18 is made to journal about the same, 2l is an alignment bearingwhich forms a bearing for 20 and at the same time insures that the samewill o erate in a straight line which is essential. ecured to the lowerend of the stem 20 is avroller bearino 22 which is made to engage andfollow the path or groove 23 located within the face of cam disk 24. A.rotative motion as shownl by the arrow is imparted to cam disk 24 asshown in Fig. 1, through the action of the chain 25 Wh1ch is driven bysprocket 26 mounted u on crank 8, this chain also enwhich the cam disk24 is made fast.

The carbureter side of the c linder has inlet manifold 29 attached tothe c linder by means of bolts 30 and has rncunte therein spring undertension 31 mounted upon valve stem 33 of valve 32, this valve is made toseat against a valve sea-t located in the inner end of inlet manifold29, and the same can be easily removed or repaired by simply removingthe manifold and by so doing the removal of the valve, valve stem,spring and all is accomplished at the same time.

Mounted upon the exhaust side of the cylinder is the exhaust manifold 34which is secured to the cylinder wall by means of bolts or otherfastenin 35. Also secured to the exhaust manifol 34 is a screw plug 36havin a bearing therein for the journaling o the valve stem 37 which hasa valve head on its inner end 38 seating to a pro er bearing or seatprovided within the is provided upon this valve by means o thecompression spring 39 and the same is housed by means of housing 40.

In order that the cylinder may be bored to a true diameter throughoutits whole length slits 41 are provided in the inlet andv exhaust portsas shown at 41 in Fig. 3,. this provides a means for the safe passage ofthe attacca piston rings past the ports without the same being damagedin their passage.

The spark plug is shown at 42, and the bearing of the stem of the upperpiston is shown at 43 which is located in the piston head. To providemeans for the free passage of the upper piston without creating of avacuum on its down stroke, and compression on the up stroke ports 44are' provided within the piston head.

F rom the foregoing specification and dcscription it will be clearlyunderstood the operation of my two cycle engine, but a brief descriptionof one cycle of operation may more clearl explain its operation so thatany one sk1lled in the art could construct and operate the same,'afterthe assembly of the motor and its operation is begun the cycle ofoperation would be as follows-In Fig. 2 the beginning of a cycle ofoperation is about to begin, the power piston is at the bottom of thestroke and the exhaust valve has been closed, the exhaust piston, or theupper piston has also reached the bottom of its stroke, and it will notreturn in its upward travel, the same being accelerated by the shape ofthe slot in the cam disk which raises Athe same, as the same travels inits upward sit-ion the' inlet valve is opened and the resh charge of thecombustion mixture is admitted, this being accomplished the lower orpower piston closes the inlet port valve by its passing the inlet portand the compressing of the mixture is accomplished as shown in Fig. 1,the explosion now takes place and the power piston is driven downwarduntil the same passes the exhaust port and the exhaust valve is openedby the pressure and the exhausting of the exploded gases is complete dueto the action of the upper or exhaust piston completing the dischargingof the saine. It will thus be seen that the cycle of operation isvcomplete, and that a two cycle en 'ne has been created.

Having thus vdescri ed my invention l wish to make the following claimthereforlln a two-cycle internal combustion engine, a cylinder, a pairof pistons reciprocating in said cylinder, packing rings carried by saidpistons, circular exhaust and intake ports located in the walls of saidcylinder at points within the range of travel of both pistons, aplurality of hars positioned in said ports and secured at their oppositeends to the cylinder to extend in the direction of travel of the pistnnswhereby damage to said rings while passing the ports will be eliminated,and means Jfor actuating said pistons.

RUDOLPH J. BOEHMER.

